Primary IgA nephropathy is generally considered a benign disease, but progression to renal failure is not uncommon and a rapidly progressive course is observed in some cases, especially when extensive epithelial crescents are present. Circulating IgA-containing immune complexes (IgAIC) seem to play the most important pathogenetical role, hence the authors adopted plasmapheretic treatment in association with immunosuppressive drugs for 1 patient affected by primary IgA nephritis, with florid crescents and progressive renal failure. IgAIC decreased significantly after each plasma exchange and finally returned to normal values; over the same period urinary protein loss and heavy microscopic hematuria gradually disappeared and renal function was completely recovered.